Mikhail Timofeyevich Kalashnikov was a railroad worker drafted into the Red Army in 1938, where be did some engineering and design work before becoming a tank commander. He was seriously injured in battle in 1941, and while recuperating in a Soviet hospital he conceived of an improved sub-machine gun. When released from the hospital he showed his sketches to superiors, and was assigned to weapons design work, where over the next several years and numerous design improvements his team developed a new weapon with a gas operated action, and an extremely lightweight mechanism that is easy to assemble and disassemble. The Automatic Kalashnikov or AK-47, named for the 1947 launch of its manufacture, was chosen as the Soviet military standard in 1949.

The AK-47 is instantly recognizable by its curved magazine, half-wood half-steel construction, a fixed metal site over its muzzle, and its characteristic explosive popping sound when fired. It is not as accurate as the M-16, but its less complex design makes the AK-47 far less susceptible to jamming and other mechanical problems. Over subsequent decades and numerous redesigns into the 21st century, it has been a weapon of choice for the military in many nations, and also a favorite of insurrectionists, criminals, and terrorists. "I'm proud of my invention," Kalashnikov said in a 2002 interview, "but I'm sad that it is used by terrorists. I would prefer to have invented a machine that people could use and that would help farmers with their work — for example, a lawnmower."

Kalashnikov also designed small arms for the Soviet Army, and helped develop several different machine guns, but none have became as famous and ubiquitous as the AK-47. It is the world's most commonly used combat weapon, with more than 100,000,000 manufactured as of 2010, and in many countries a used but fully functional AK-47 can be had for the equivalent of about ten American dollars, or less.

Its inventor has been honored with numerous awards from the Soviet and its successor Russian government, but says he has received only a state pension for his weapons work. He has, however, licensed his name on products including vodka, knives, and umbrellas. Even towards the end of his life, Kalashnikov remained in good health, working four days a week as chief weapons designer at Izhmash, the company that produces his namesake rifle.